Utilizing the heat of gases



Sept. 3, 1929. c. G. HAWLEY UTILIZING THE HEAT OF GASES Filed March 11, 1926 .Fl 1 IIIIIIML Patented stat. 3, 1929.

UNITED STATES PATENT OFFICE.

CHARLES GILBERT HAWLEY, OF CHICAGO, ILLINOIS, ASSIGNOR TO CENTEIFIX OOR- IPORATION, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

UTILIZING THE HEAT 0]? GASES.

Application filed March 11, 1926. Serial No. 94,083.

My invention relates to means for utilizing the heat ofwaste gases as in boiler stacks and the like by the employment of means of less size, of less weight, of less initial cost, and of less cost of upkeep than the tubular feed water heating economizers usually employed for the purpose.

A further ob ect of the invention is to' provide for the heating of water, not after the indirect manner of an economizer, but by direct contact with hot stack gases, thereby retrieving the heat from the gases and at the same time throwing downthe dust therein and, subsequently, to provide for the purification of the dust befouled hot water and its utilization while still hot.

The invention will very readily be understood on reference to the accompanying drawing; in which Fig. 1 is an elevation illustrating a. steam boiler and stack and the several appliances which I have orignated for application thereto in carrying out this invention. Fig. 2 is an enlarged vertical section of the combined dust collecting and water heating unit or economizer embodying the invention; and Fig. 3 is a horizontal section thereof on the line 33 of Fig. 2.

I shall first describe the several parts illustrated and then enlarge upon the above defined process of utilizing the heat of the stack gases. Fig. 1 represents an ordinary water tube steam boiler 2, of which 3 is the breeching, and 4 the smoke stack. Between the breeching and the stack I interpose the dust collecting and feed water heating economizer 5, hereinafter described in greater detail.

The hot gases from the combustion spaces of the boiler enter the bottom of'the economizer 5 and pass into the same through a so-called centrifugal or tangentially bladed tuyere 6. By that means the gases are caused to whirl therein, thereby sending the body of the gases and the contained dust laterally against the inner wall of the economizer casing. Whirling upward therefrom the gases pass into the base of the stack 4. But, meantime they are showered with water which is received through a spray box 5' on the top of the economizer casing and supplied with water under pressure from some such source as the tank 7 Lest the draft be too greatly lessened stack section containing the same is made to i take the form of a Venturi tube 4. I

The temperature of the water is very much increased within the economizer and collecting in the bottom thereof it is removed as through a large drain pipe 9.. Preferably,

the upper part of the economizer is provided with an expansion space 5 which recoversso much of the water and contained dust as may be lifted to the top of the economizer by the whirling gases. That portion also has a drain pipe, 9. The drains join in the direction pipe 10. The latter is a part of the downgoing' impact section of the filter 11, by means of which the dust contained in the water is separated and may finally be discharged into the pit 12. Leaving the filter 11 through the upgoing direct-ion pipe 13 the dust freed water is projected upwardly into the bottom of the gas removing section 14:,preferably used as an adjunct of the filtering apparatus. The water leaves the filter through the pipe 15; 16 represents a-receptacle for such oils and tars as may be withdrawn from the top of the chamber 14, through the overflow pipe '17. The parts embraced between those numbered 10, 15 and 17, though of different form, fall within the scope of the invention which is described and claimed in my companion applications S. N. 93,275. S. N. 93,462, and do not require further description herein. They serve effectively to remove the dirt and the gases from the stack heated water. Thereupon, the water enters the apparatus 18, in which it is subjected to any chemical treatment that may be required. The parts 19 and 20 represent those elements of the treating apparatus through which the chemicals and fresh water are introduced. 21 represents the sludge pit beneath the treating tank 18. The treated water passes through pipe 22 to the feed water heater ,2?) andthence, by way of the pipe 24, to the feed water pump 25. The feed Water from the latter is conveyed to the' boiler through the feed water line 26.

27 represents the steam main leading from the boiler. 28 represents the exhaust steam return which is usually connected with the feed water heater 23.

From the foregoing it will be evident that in my invention the otherwise waste heat of the stack gases is successfully conserved, and in the present instance returned to the boiler, at the same time accomplishing the admirable result of preventing the escape to the atmosphere of ash, carbon, and tar particles.

From the foregoing it will also be ap-' parent that my invention, both as to the described method of preventing the discharge of dust, and the method of utilizing the heat of the gases with good eifect may be utilized in various other industries.

The novel dust eliminating apparatus preferably partakes of a form such as is illustrated in Figs. 2 and 3. It may be constructed throughout of sheet metal. It never contains a great amount of water and, therefore, does not require a remarkable foundation or sup porting structure. The economizer may conveniently serve as the base of the stack proper and may be supported by the usual roof structure often depended on for the support of such stacks. However, the invention is not limited thereto, as the economizer may be in a separate structure that is included or cut into the smoke flue between the boiler or other combustion chamber and the stack.

The economizer proper comprises the cylindrical chamber 29, conveniently provided with a hopper bottom 30, and having its top closed by the perforated plate 31, the spray box 5', and the enclosing jacket 5". The cylinder proper 29 terminates short of the plate 31 where it is provided with the outstanding flange and leaving the circumferential opening 32, through which opening communication is established between the interior of the casing proper 29 and the external jacket 5". As the latter receives considerable water and some dust it is provided with an inclined bottom 33, so that at the bottom of the jacket a pocket 34 is formed for the collection of water and dust. This pocket is drained by the pipe 9. The hopper portion 30 is drained through the preferably valved outlet 30' and the pipe 9. The gases enter through the upturned elbow 35, which joins the breeching or smoke flue at the flange 36. The upturned end of the large elbow is centrally positioned in the cylindrical casing and at its upper end is equipped with the tangentially bladed tuyere T. The latter comprises a bottom ring 37, the many blades 38, and the preferably conical top, cap or plate 39. The tuyere T is attached to the flange 35, at the top of the inlet pipe 35 and does not rotate but, by reason of the substantially tangential direction of the gases through the many tuyeres T, the whole ody of gas within the casing is set into rapid rotation. The perforated plate 31 and the box 5 contain a central opening of the same or greater size than the pipe 35 and accommodating a corresponding outlet etO. This last may be the base ofthe stack proper, as before explained. Preferably, the lower end of the stack 40 is marked by a downwardly extenda ing flange 41 hanging below the perforated plate, to obviate an uptake of water.

The many dotted lines of Fig. 2 represent the multitude of streams or sprays that are formed at the top of the economizer and rain downward therein against the upward moving gases. The rotation of the body of gas within the casing is generally represented by the arrows in Figs. 2 and 3, but can be better explained as having'the eflect of thoroughly mixing the sprays of water with the gas and, meantime, sending the gases and their burden of dust particles centrifugally against the wetted walls of the economizer. Clearly, the water introduced takes up much heat from the hot gases and, importantly, throws down the dust so that it drains away with the water through the pipe 9. Due to the strong whirling action within the casing some of the dust and water is expelled upwardly and outwardly over the top flange of the casing 29, thus falling into the jacket 5", to be drained away through the pipe 9'.

Attention is called to the fact that in event of the failure of the supply of water so that the economizer runs dry it still continues to function very successfully as a dry dust catcher. In thatevent, most of the dust is raised and is finally deposited in the acket 5 and, because of such emergencies it is best to provide the bottom of the jacket 5" with a capacious drain pipe 9. At such times the dry dust drains down into the filter pocket 11, which continues to function as a receptacle for the dirt.

Various modifications of this invention an outlet at its top, in combination with an inlet rising centrally within said casing, means at the top of said inlet for setting the gases into rotation within the casing below and outward of said outlet, means for spraying liquid into the top of said casing, and;

means at both top andbottom of said casing for the removal of liquid and dust therefrom.

2. Gas purifying apparatus comprising a cylindrical casing which is closed at the bottom and open at the top, a whirlpromoting said casing, and said transverse member coninlet tuyere positioned centrally in a lower taining an outlet opening which is co-axial part of said casing, a transverse member of with said tuyere and is above the level of the 10 larger diameter than said casing and positop of said casing.

5 tioned above the top thereof, a jacket com- In testimony whereof I have hereunto set bined with said members and therewith formmy hand this 9th day of March, A. D. 1926. ing a centrifugal reception space at the top of CHARLES GILBERT 

